Hybrid lenses, which consist of different materials, are known in the form of glass polymer hybrids from the prior art. The latter consist of a glass, generally in spherical shape, which is surrounded by a polymer, generally with an aspherical outside shape. The hybrid lenses thus consist of at least two different materials with different refractive indices and different dispersion. By using at least one other material, the imaging properties of the hybrid lens, in particular refractive power, chromatic aberration and other imaging defects, can be suitably adjusted.
Usually glass/polymer hybrid lenses are used, for example, for use in optical pick-up systems. The refractive index of glasses or polymers is relatively low, however, or the dispersion is usually relatively high. In addition, disadvantages of the plasticity of glasses are compensated for by the combination with the plastic polymer that can easily be deformed.
While precision lenses made of glass must be ground at great expense and finished, production processes, such as, for example, injection molding or pressing, with which lens elements can be produced in a simple way and without expensive surface finishing, are increasingly demanded for reasons of cost. Lenses or lens systems that are produced in such a way increasingly find use now in consumer electronic devices, for example as single lenses or lenses of hand-held cameras or digital cameras. With the material combinations that are currently available, optical imaging defects can often be compensated for only inadequately, however, since the refractive index of glasses is comparatively low or the dispersion is too high. This limits the achievable optical qualities with respect to resolution, monochromatic defects (for example spherical aberration) and chromatic defects, and with respect to other optical properties.
U.S. Pat. No. 5,846,638 A discloses the manufacturing of hybrid optical elements using a particular bonding process, which requires an optical contact between the surfaces to be connected, which can be achieved only by an extremely fine polishing or lapping of the surfaces. This connecting technique is possible only for the connecting of fiat surfaces by bonding. A curved surface of a lens in terms of this application cannot be connected to another material in the meaning of this application.
DE 103 19 706 A1 discloses the formation of small glass elements by quick immersion of a glass melt in a cooling liquid.
US 2004/0105155 A1 discloses a lens array that consists of several individual lenses, but no optical hybrid lens in the meaning of this application. For the production, first a liquid to be hardened is put into a form, and then a substrate is applied. Finally, a lens array is produced. The sequence of steps can also be varied. For this purpose, the use of a glass ceramic is disclosed, but not an optical ceramic in terms of this application.
US 2005/0185300 A1 discloses an optical element having a stepped lens such as a Fresnel lens and a light-diffusing element, which is arranged only in a central region of the element. This enables to suppress the light source or luminous body image. It is also possible to reduce faults of illuminating beam paths given a suitable choice of the diffusing structure and the geometric dimensioning thereof. The stepped lens and/or the diffusing screen can be made of glass or glass ceramic, which is not an optical ceramic in the meaning of this application.